The invention relates to the cycling of loads within a building for saving energy.
In recent years, with the renewed, increased interest in energy conservation, and particularly as a result of increases in the cost of fuels and a concomitant decrease in their availability it has become desirable and economically responsible to operate the various loads within a building in an energy conserving manner. Such buildings may, for example, comprise a plurality of floors each floor having both exterior and interior offices, zones or spaces and each floor having at least one fan system with associated temperature controlling apparatus. It can readily be seen that by cycling the temperature controlling apparatus and fans in the fan system on and off instead of running them continuously as had been done in the prior art, a substantial amount of energy can be saved.
In the prior art, these temperature controlling apparatus and fans were cycled independently of the physical condition which may be, for example, temperature or humidity. Cycling these loads without feedback from the physical condition resulted in erractic control within the building. In an attempt to solve this erractic behavior, the prior art controlled the cycling of the loads within the buildings according to outdoor temperature. The use of an outdoor temperature sensor or other type of condition sensor, however, did not totally solve the problem because the indoor temperature or physical condition is effected by conditions other than the outdoor temperature.
In the present invention, the loads of the building are cycled at a predetermined rate and the off time within each cycle for each load or selected loads within the building is reset by a temperature sensor located within the building. This system not only compensates for the outdoor air temperature, but also compensates for the outdoor air which infiltrates into the building, the skin effect of the wind as it wipes over the building exterior surface and effects of solar radiation on the building. By resetting the off time according to indoor temperature or physical conditions, the physical condition within the building is controlled at a much more comfortable level.
Moreover, in load cycling systems of the past, particularly those which utilized computers for controlling the cycling of the loads within the building, information which was utilized by the computer was stored in memory on a point-by-point basis. By storing this information in this manner, a large amount of memory was used up for merely providing the design parameters to the program for use in controlling the cycling of the loads.
In the present invention, information relating to the time sequence of operation of the loads is stored within a schedule and the operating characteristics or design parameters of each load are stored within tables. A schedule may be applicable to several loads and certain of the information in a table can also relate to several of the loads. Thus, certain information can be stored in one location and still be applicable to several loads rather than having to store this information a plurality of times with respect to each of the loads within the building resulting in the saving of a large amount of storage space.